Drag and Drop 2.3.1

static
Class YAHOO.util.DragDropMgr

DragDropMgr is a singleton that tracks the element interaction for
all DragDrop items in the window. Generally, you will not call
this class directly, but it does have helper methods that could
be useful in your DragDrop implementations.

Provides additional information about the the current set of
interactions. Can be accessed from the event handlers. It
contains the following properties:
out: onDragOut interactions
enter: onDragEnter interactions
over: onDragOver interactions
drop: onDragDrop interactions
point: The location of the cursor
draggedRegion: The location of dragged element at the time
of the interaction
sourceRegion: The location of the source elemtn at the time
of the interaction
validDrop: boolean

Flag to determine if we should stop the propagation of the events
we generate. This is true by default but you may want to set it to
false if the html element contains other features that require the
mouse click.

Helper function for getting the best match from the list of drag
and drop objects returned by the drag and drop events when we are
in INTERSECT mode. It returns either the first object that the
cursor is over, or the object that has the greatest overlap with
the dragged element.

My goal is to be able to transparently determine if an object is
typeof DragDrop, and the exact subclass of DragDrop. typeof
returns "object", oDD.constructor.toString() always returns
"DragDrop" and not the name of the subclass. So for now it just
evaluates a well-known variable in DragDrop.

Refreshes the cache of the top-left and bottom-right points of the
drag and drop objects in the specified group(s). This is in the
format that is stored in the drag and drop instance, so typical
usage is:
YAHOO.util.DragDropMgr.refreshCache(ddinstance.groups);
Alternatively:
YAHOO.util.DragDropMgr.refreshCache({group1:true, group2:true});

Ends the current drag, cleans up the state, and fires the endDrag
and mouseUp events. Called internally when a mouseup is detected
during the drag. Can be fired manually during the drag by passing
either another event (such as the mousemove event received in onDrag)
or a fake event with pageX and pageY defined (so that endDrag and
onMouseUp have usable position data.). Alternatively, pass true
for the silent parameter so that the endDrag and onMouseUp events
are skipped (so no event data is needed.)

Parameters:

e <Event>
the mouseup event, another event (or a fake event)
with pageX and pageY defined, or nothing if the
silent parameter is true

This checks to make sure an element exists and is in the DOM. The
main purpose is to handle cases where innerHTML is used to remove
drag and drop objects from the DOM. IE provides an 'unspecified
error' when trying to access the offsetParent of such an element